I think in some cases, schools have the right to penalize students for what is said online or for out of school behavior based on the seriousness of their offence. If they threaten them or give out the teachers adress or something like that, it would be serious. I think if you just say that you hate the teacher, it is an ok thing to do. As long as they are not treatened in any way, I think online slander or out of school behavior is fine.
I think the limits of internet speech is blackmail, threats, and stalking. If you do any of those things online, you should get suspended and hopefully arrested. I think just saying that you hate the teacher is an ok thing to do. You are not doing anything physically or mentally bad to them. I think they should be the mature one and just brush off the comments.
I think the school should have the rights to limit student expression within the school. If the school has no control over the students expression, then they can't stop any physical or mentally attacks on the person, then the school should not exist. Even if the students emotionally hurts a teacher, they should get punished for it durring school hours. The teachers should have any rights as to suspend a student based on an online bashing where only the people who hate you would post.
No student would stick up for the teacher on a such thing as facebook. They would be hurt more than the teacher would. The teacher would only have to deal with words against him/her. While the student will have to deal with the bashing and possibly physical altercations for trying to stickup for the teacher.
In my opinion, if you are out of school and only post emotional hurting comments; the student should not be suspended. I also think if the student posts mental or physical messages on the web; they should be suspended or even expelled. As long as the student doesn't blackmail, stalk, or threaten the teacher outside of school; they should be fine. As long as you don't say something very hurtful and not a random name, they shouldn't have you expelled for it. I think internet speech and school talk are two diverse things and should be seperated in that way.